With a growing elderly population dementia has become a major public health problem. Since the incidence of dementia increases with advancing age it is destined to become even more important as the population ages. Preventive strategies require a better understanding of the incidence and precursors of dementia, and specifically of dementia occurring after cerebral infarction, "multi-infarct dementia", based on prospective data. The aim of this proposal is to continue and extend the five years of prospective study of dementia in the Framingham Study cohort of 2400 men and women, aged 62 to 94 years and documented to be free of dementia on Exam 17 in 1982. Mechanisms for the detection by Folstein Mini-Mental State Exam screening and confirmation of dementia by detailed neurological and neuropsychological evaluations and at autopsy by neuropathological examination are in place and criteria for classification of dementia subtypes have been developed. In this general population sample a major goal is to determine the incidence and precursors of dementia generally and of specific dementia subtypes and during the proposed 5 years of study an additional 200 cases of dementia are projected to occur. Since the Framingham Study has prospectively and systematically measured risk factors for cardiovascular diseases including stroke over nearly 4 decades, a unique opportunity exists to relate these previously determined atherogenic risk factors to the development of dementia generally and to "multi-infarct dementia" specifically. Other prospective data such as family history of dementia and stroke, medical history, and sociodemographic factors can also be examined in relation to the development of Alzheimer's disease and other specific subtypes of dementia, notably "multi-infarct" dementia.